<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <meta http-equiv="X-UA-Compatible" content="ie=edge">
    <title>函数</title>
</head>
<body>
    <script>
        // salary 形参
        function calcTax(salary){
            // 计算三险一金基数
            var baseSalary = 0;
            if(salary > 7662){
                baseSalary = 7662;
            }
            else{
                baseSalary = salary;
            }
            // 计算三险一金
            var sanXianYiJin = baseSalary * (0.08 + 0.02 + 0.005 + 0.12);

            //3.应纳税所得额
            var yingNaShuiSuoDeE = salary - sanXianYiJin - 3500;

             //确定税率和速算扣除数
             var shuiLv = 0;
             var suSuanKouChuShu = 0;
             var tax = 0;
             if(yingNaShuiSuoDeE <= 0){
                 //不交税
                 tax = 0;
             }
             else{
                if(yingNaShuiSuoDeE <= 1500){
                     shuiLv = 0.03;
                     suSuanKouChuShu = 0;
                 }
                 else if(yingNaShuiSuoDeE <= 4500){
                     shuiLv = 0.1;
                     suSuanKouChuShu = 105;
                 }
                 else if(yingNaShuiSuoDeE <= 9000){
                     shuiLv = 0.2;
                     suSuanKouChuShu = 555;
                 }
                 else if(yingNaShuiSuoDeE <= 35000){
                     shuiLv = 0.25;
                     suSuanKouChuShu = 1005;
                 }
                 else if(yingNaShuiSuoDeE <= 55000){
                     shuiLv = 0.3;
                     suSuanKouChuShu = 2755;
                 }
                 else if(yingNaShuiSuoDeE <= 80000){
                     shuiLv = 0.35;
                     suSuanKouChuShu = 5505;
                 }
                 else{
                     shuiLv = 0.45;
                     suSuanKouChuShu = 13505;
                 }

                 tax = yingNaShuiSuoDeE * shuiLv - suSuanKouChuShu;
             }
             return tax;
        }
        var geShui = calcTax(7000);
        console.log(geShui);

        calcTax(12000);
    </script>
</body>
</html>